Multiple fuse device

ABSTRACT

A box-like enclosure with one side open is adapted to receive three pairs of generally L-shaped terminal members. Between each pair of L-shaped members conductive fusible means extends, and the remainder of the enclosure is filled with a suitable arcquenching material such as sand. In accordance with the invention, the L-shaped members are received and held in place in the enclosure during assembly and before the open side is closed. The means for retaining the L-shaped terminal members in place includes a pocket in the enclosure receiving one end of a corresponding terminal member, and each L-shaped terminal member has a projection formed so as to cooperate with an outer side wall of the enclosure. The net result of these positioning means is that the L-shaped terminal members are held in place during assembly without the use of separate fastening means, whereby the fusible conducting means may be assembled between the pairs of Lshaped terminal members.

United States Patent [191 Klein [451 June 18, 1974 MULTIPLE FUSE DEVICE Keith W. Klein, Simsbury, Conn.

General Electric Company, New York, NY.

Filed: Dec, 29, 1972 Appl. No.: 319,727

Inventor:

Assignee:

[52] US. Cl 337/148, 337/146, 337/161,

337/231 Int. Cl. H01h 71/20 Field of Search 337/146, 148, 186, 188,

[56] References Cited UNITED STATES PATENTS 7/1971 Wilson 335/231 W X 6/1972 Kozacka 337/146 6/1972 Salzier 337/231 X 10/1972 Belcher et a1 337/231 X [5 7] ABSTRACT A box-like enclosure with one side open is adapted to receive three pairs of generally L-shaped terminal members. Between each pair of L-shaped members conductive fusible means extends, and the remainder of the enclosure is filled with a suitable arc-quenching material such as sand. In accordance with the invention, the L-shaped members are received and held in place in the enclosure during assembly and before the open side is closed. The means for retaining the L- shaped terminal members in place includes a pocket in the enclosure receiving one end of a corresponding terminal member, and each L-shaped terminal member has a projection formed so as to cooperate with an outer side wall of the enclosure. The net result of these positioning means is that the L-shaped terminal members are held in place during assembly without the use of separate fastening means, whereby the fusible conducting means may be assembled between the pairs of L-shaped terminal members.

flei ia D i u PAIENTED I 81974 FIG. 2

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FIG. 3

I MULTIPLE FUSE DEVICE FIELD OF THE INVENTION The present invention relates to multiple fuse devices, and particularly to such devices which include an elongated generally box-like insulating enclosure receiving a plurality, such as three, pairs of terminal members between which fusible conductive members are received and later embedded in arcquenching material.

BACKGROUND OF THE INVENTION Multiple fuse devices of the type described have been provided in accordance with prior art. Thus US. Pat. No. 3,281,555, A. J. Fister, Oct. 25, 1966, US. Pat. No. 3,593,251, J. C. Wilson, July 31, i971, and US. Pat. No. 3,671,910, Kozacka, June 20, 1972, all disclose multiple fuse devices comprising a generally boxlike insulating enclosure having three pairs of terminals supported therein with portions projecting outside of the enclosure for connection. Conductive fusible means extends between the terminal members, embedded in arc-quenching sand material. One of the advantages of such multiple fuse devices is that fiisible means can be provided for three poles or circuit paths in a very compact manner, requiring much less space than three individual cylindrical type fuses.

In accordance with the structure disclosed in the F ister and Wilson patents, a plurality of sub-assemblies are first assembled, each comprising a pair of opposed strap-like terminal members supported in a predetermined spaced-apart relation by rigid insulating spacer members and with conductive fusible members extending therebetween. Each of these sub-assemblies is inserted into the box-like enclosure through an open side, and retained therein by an insulating cover member.

In accordance with the structure disclosed in the K- zacka patent, the terminal members are first inserted in the insulating housing member and are fastened thereto. The fusible members are then assembled such as by sliding them into grooves formed in the respective terminal members, the connection being completed by a soldering operation.

Each of these techniques has disadvantages. For example, in the Fister and Wilson technique, the subassemblies comprising the terminal members and the insulating spacer members must first be assembled, and the fusible members then attached between the terminal members. These sub-assemblies must then be assembled into the insulating housing. As will be pointed out in further detail, the structure of the present invention greatly simplifies and speeds up the assembly technique in comparison with that of the Fister and Wilson patents.

The structure of the Kozacka patent requires separate fastening means to be provided for attaching the terminal members to the insulating housing before the fusible conductive members can be inserted and connected. This structure not only requires separate fastening means (screws) and assembly operations for inserting and fastening them. but also requires that holes be drilled in the insulating housing, since these holes extend in a direction such that they cannot readily be formed in the basic molding operation which fonns the housing.

OBJECTS OF THE INVENTION It is a primary object of the present invention to simplify the construction and assembly techniques required for a multiple fuse assembly of the type shown in the aforesaid patents.

It is a more particular object of the invention to provide a multiple fuse assembly of the type described which does not require the construction of separate sub-assemblies outside of the main insulating enclosure and subsequent assembly of these sub-assemblies into the enclosure.

It is another particular object of the invention to provide a multiple fuse assembly of the type described which does not require separate fastening means for the terminal members.

It is another object of the invention to provide a multiple fuse assembly of the type described which permits a speedier and simpler assembly of the device, thereby reducing the time and cost necessary to construct the device.

SUMMARY OF THE INVENTION In accordance with the present invention, a multiple fuse device of the type described is provided in which formations in the insulating housing, and formations on the respective terminal members permit the simple insertion of the terminal members in the housing before the open wall of the housing is closed. These formations retain the terminal members in proper location whereby the conductive fusible members may be inserted and connected to the terminal members by a simple operation, following which the open side is enclosed by an insulating wall. These formations include pockets receiving an end portion of the respective terminal members which prevent movement of the terminal member away from the desired position. In addition, the formations on the terminal members adjacent the opposite end thereof cooperate with the outer side wall of the insulating enclosure and insure against movement of this end of the terminal member away from its desired position. The insulating housing is thereby caused to serve as an assembly fixture or jig positioning the respective terminal members and facilitating the further assembly of the conductive fusible members without the necessity of separate fastening means for the terminal members.

DESCRIPTION OF THE DRAWING FIG. 1 is an exploded sectional view of a multiple fuse device constructed in accordance with the invention and taken substantially along the claim indicated by the numerals ll of FIG. 3.

FIG. 2 is a plan view of the multiple fuse device of the invention taken along the plane indicated by the numerals 22 of FIG. 1.

FIG. 3 is a top plan view of the multiple fuse device of FIG. 1.

FIG. 4 is a plan view of a conductive fusible member utilized in the multiple fuse device of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawing, the invention is illustrated as comprising a generally box-like elongated insulating enclosure 10 having one open wall 12 adapted to be closed by an insulating cover member 14.

Referring to FIG. 2, three pairs of opposed generally L-shaped terminal members 16A-16B, ISA-18B, and 20A-20B are inserted in the insulating housing before the cover member 14 is put in place. The L-shaped terminal members referred to are held in place during assembly in a manner to be described.

After the terminal members have been assembled in place, a multiple fusible link member 22 is inserted between each pair of terminal members by having edge portions 22A and 2213 received in corresponding slots 24A-24B, 26A-26B, and 28A-28B, in the corresponding terminal members 16A-16B, ISA-18B, and A-20B. The conductive fusible members 22 are then permanently fixed in place by suitable means, such as by soldering. Each conductive fusible member 22 also includes parallel extending conductive fusible link portions 22C, 22D, 22E, 22F, 22G, 22H.

For the purpose of positioning the terminal members 16A and 168, the insulating housing 10 is provided with conforming-shaped recesses 17A and 17B. Corresponding recesses or pockets, not shown, are also provided for the other terminal members ISA-18B and 20A-20B.

In addition, each of the terminal members 16A, 16B, is provided with a projection 19A and 198 respectively. The projections 19A and 19B are positioned so that when the corresponding terminal member is in assembled position as shown in FIG. 1, the projection is closely adjacent the outer wall surface of the housing The positioning of the ends of the terminals 16A, 16B in the corresponding recesses or pockets 17A, 17B combined with the positioning of the projections 19A, 19B closely adjacent the outer wall surface of the housing 10 has the effect of positioning the terminals 16A, 168 in predetermined positions in the housing 10 and of preventing any substantial movement of the terminals in any direction other than straight-line movement away from the recesses or pockets 17A, 17B. The same is true with regard to the terminals 18A, 18B and 20A, 20B. Movement of any of the terminals 16A, 16B, 18A, 18B, 20A, 208 in such straight-line direction away from the corresponding recesses or pockets is prevented, when the device is assembled, by the closure member 14.

In accordance with the invention, and utilizing the above-described structural features, assembly of the multiple fuse device of the invention is preferably carried out in the following manner.

The spring and plunger members 32, 30, together with the connectors 32A are inserted in the corresponding chambers, and the restraining wires 34 are connected to the corresponding connector members 32A. A suitable flat plate restraining means is placed against the upper surface of the housing 10 to hold the springs 32 and plungers 30 in place, and the assembly is then inverted and placed on a suitable support with the open wall 12 of the enclosure 10 facing upwardly.

The terminal members 16A, 16B, 18A, 18B, 20A, 20B are next inserted in mounted position, with the end of each terminal member received in a corresponding recess or pocket such as 17A, 17B, and the projections such as 19A, 10B closely adjacent the outer wall surface of the enclosure 10. By this means, the pairs of terminal members 16A-16B, l8A-l8B, and 20-A-20B are each spaced apart the correct distance so that a fusible member such as member 22 may be slid into slots or grooves such as slots 21A, 21B in terminals 16A, 16B respectively.

The fusible members 22 are then permanently conductively connected to the corresponding terminal members by flowing melted solder into the slots or grooves 21A, 21B, etc.

The remaining steps in assembly of the device are then carried out in any suitable manner. Thus the restraining wires 34 may be affixed to the corresponding terminal members such as by means of screws 44.

Following this, the closure member 14 may be assembled by suitable means such as by bolts 40 (see FIG. 3). A suitable arc extinguishing medium, such as fine sand, may then be introduced into the housing 10 through openings such as 14A in the closure member 14. The openings 14A may then be sealed by completing the filling of the housing 10 and the chamber 143 of the closure 14 with sealing material such as an epoxy resin which is introduced in liquid form and subsequently hardens to a solid form.

It should be noted that the external portion of the terminals 16B, 18B and 20B lie in a plane which is offset from the plane of the external terminal portions 16A, 18A, 20A by an amount substantially equal to the thickness of the terminal members. Thus the portions 16B, 18B, 203 may overlie corresponding terminal portions of any device to which they are connected, and the portions 16A, 18A, 20A will be in substantially the same plane as the terminals of the device to which the unit is connected.

While the invention has been shown in one particular embodiment, it will be appreciated that various modifications thereof may be made. It is therefore intended, by the appended claims, to cover all such modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A multiple fuse device comprising:

a. a generally rectangular, box-like housing of insulating material having a top, bottom and opposed side and end walls, said bottom wall being open;

b. a generally rectangular closure member of insulating material closing said open bottom wall of said housing;

c. at least one pair of generally L-shaped terminal members of electrically conductive material, each of said terminal members having a first elongated portion within said housing and a second portion externally accessible for making electrical connection thereto;

d. said housing and said terminals having cooperating formations preventing all movement of each of said terminals except movement in a straight-line direction perpendicular to said open bottom wall;

e. a conductive fusible member extending between each said pair of terminal members;

f. each of said pairs of terminal members having portions interfitting with portions of the corresponding one of said fusible members when each of said pairs of terminal members are spaced apart a predetermined distance, said housing serving to retain and position said terminal members of each of said pairs in said predetermined spaced relation before assembly of said closure whereby said fuse device may be assembled by inserting said terminal members into said housing through said open wall and said fusible member for each of said pairs of tenninal members may be inserted into said housing through said open wall into interfitting relation with said terminal members;

g. means permanently conductively connecting said fusible member to said terminal members and means fixedly attaching said closure member to said housing so as to close said open wall of said housing and to retain said terminal members and said fusible members in said housing.

2. A multiple fuse device as set forth in claim 1 wherein said formations of said insulating housing and said terminal members include a recess in said housing for each of said terminal members, said recess receiving in closely conforming relation at least the free end portion of said elongated portion of said terminal member.

3. A multiple fuse device as set forth in claim 2, said formation of said housing and said terminal members including a projection on said second portion of each of said terminal members, said projections being positioned closely adjacent an outer side wall of said housmg.

4. A multiple fuse device as set forth in claim 1 wherein said interfitting portions of said fusible members and the corresponding ones of said terminal members comprises an elongated slot in said first elongated portion of each of said terminal members, said slots being dimensioned to closely receive a corresponding portion of the corresponding fusible member whereby said terminal members and the corresponding fusible member may be assembled in said housing by inserting said terminal members into said housing through said open bottom wall without positive fastening means and said corresponding fusible members inserted by a straight-line movement with portions thereof received in said slots of said terminal members.

5. A multiple fuse device as set forth in claim 1 wherein said device comprises three pairs of terminal members and a corresponding fusible member for each of said pairs of terminal members.

6. A multiple fuse device as set forth in claim 5 wherein said second portions of a first one of each of said pairs of said terminal members are disposed at one side of said housing in co-planar relation in a first predetermined plane and said second portions of the other of each of said pairs of said terminal members are disposed at the side of said housing opposite said one side in co-planar relation in a second predetermined plane extending parallel to said first plane and offset from said first plane by a distance substantially equal to the thickness of said tenninal members. 

1. A multiple fuse device comprising: a. a generally rectangular, box-like housing of insulating material having a top, bottom and opposed side and end walls, said bottom wall being open; b. a generally rectangular closure member of insulating material closing said open bottom wall of said housing; c. at least one pair of generally L-shaped terminal members of electrically conductive material, each of said terminal members having a first elongated portion within said housing and a second portion externally accessible for making electrical connection thereto; d. said housing and said terminals having cooperating formations preventing all movement of each of said terminals except movement in a straight-line direction perpendicular to said open bottom wall; e. a conductive fusible member extending between each said pair of terminal members; f. each of said pairs of terminal members having portions interfitting with portions of the corresponding one of said fusible members when each of said pairs of terminal members are spaced apart a predetermined distance, said housing serving to retain and position said terminal members of each of said pairs in said predetermined spaced relation before assembly of said closure whereby said fuse device may be assembled by inserting said terminal members into said housing through said open wall and said fusible member for each of said pairs of terminal members may be inserted into said housing through said open wall into interfitting relation with said terminal members; g. means permanently conductively connecting said fusible member to said terminal members and means fixedly attaching said closure member to said housing so as to close said open wall of said housing and to retain said terminal members and said fusible members in said housing.
 2. A multiple fuse device as set forth in claim 1 wherein said formations of said insulating housing and said terminal members include a recess in said housing for each of said terminal members, said recess receiving in closely conforming relation at least the free end portion of said elongated portion of said terminal member.
 3. A multiple fuse device as set forth in claim 2, said formation of said housing and said terminal members including a projection on said second portion of each of said terminal members, said projections being positioned closely adjacent an outer side wall of said housing.
 4. A multiple fuse device as set forth in claim 1 wherein said interfitting portions of said fusible members and the corresponding ones of said terminal members comprises an elongated slot in said first elongated portion of each of said terminal members, said slots being dimensioned to closely receive a corresponding portion of the corresponding fusible member whereby said terminal members and the corresponding fusible member may be assembled in said housing by inserting said terminal members into said housing through saId open bottom wall without positive fastening means and said corresponding fusible members inserted by a straight-line movement with portions thereof received in said slots of said terminal members.
 5. A multiple fuse device as set forth in claim 1 wherein said device comprises three pairs of terminal members and a corresponding fusible member for each of said pairs of terminal members.
 6. A multiple fuse device as set forth in claim 5 wherein said second portions of a first one of each of said pairs of said terminal members are disposed at one side of said housing in co-planar relation in a first predetermined plane and said second portions of the other of each of said pairs of said terminal members are disposed at the side of said housing opposite said one side in co-planar relation in a second predetermined plane extending parallel to said first plane and offset from said first plane by a distance substantially equal to the thickness of said terminal members. 